A sufficient number of individuals will be screened to enroll up to 326 subjects;approximately 276 subjects are expected to complete treatment through study termination (Week 26). The study population will consist of individuals currently treated with metformin, for at least 3 months prior to the study start. Subjects who have ever received exogenous insulin therapy as part of an outpatient diabetes treatment regimen are to be excluded, as are those taking oral anti-diabetic agents other than metformin within 3 months of screening (e.g., sulfonylureas, thiazolidinediones,alpha-glucosidase inhibitors, or meglitinides). Subjects may be male or female(surgically sterile, postmenopausal, or using appropriate contraceptive methods if of childbearing potential), age 18 to 75 years, inclusive, and are to have a screening HbA1c value of ≥ 7.5% and <11.0% and a screening body mass index (BMI) in the range of 25 kg/m2 to 42 kg/m2, inclusive.